1. Field of the Disclosure
The present disclosure relates to an interlock apparatus of a ring main unit, and particularly, to an interlock apparatus of a ring main unit, which controls a state between a plurality of switches disposed adjacent to each other.
2. Background of the Disclosure
Generally, a ring main unit is an apparatus that is used for monitoring, controlling, and protecting an electric system used to receive and distribute power supplied from power distribution equipment. The ring main unit is configured with an array where a circuit breaker, a switchgear, a ground, conductors, and the like are included in a structure sealed and insulated by an SF6 gas.
The ring main unit includes a circuit breaker, a load switch, a fuse, a disconnector, etc. A cable cover is detachably attached on the ring main unit, for protecting each of circuits.
FIG. 1 is a diagram illustrating a schematic configuration of a plurality of switches 11 and 12 included in a related art ring main unit.
As illustrated in FIG. 1, the plurality of switches 11 and 12 included in the related art ring main unit are supplied with power from different power supply sources. One switch 11 is continuously connected to a power supply source, and another switch 12 disposed adjacent thereto is not connected to a power supply source so as to prevent an accident from occurring.
However, the switches 11 and 12 of the related art ring main unit configured as described above do not include a separate interlock apparatus that prevents a power supply source from being connected to all of the switches 11 and 12 disposed adjacent to each other, and consequently, all of the switches 11 and 12 are respectively connected to the different power supply sources. For this reason, the insulation performance of the ring main unit is degraded due to a potential difference caused by the double supply of powers having different phase differences, and a short circuit accident occurs frequently.